The detection of physical parameters, such as the acceleration, is necessary for the regular control of passenger and freight elevators. In a known transducing device, one or a plurality of path receivers, such as movement sensors, are arranged to a cable and thus the speed, speed variations or also the antiskid of the sheathed cable driven by the elevator drive disk are detected. In this manner acceleration versus data time can be received during the elevator safety catch process by an evaluation unit connected to the path receivers and to a timer, thereby determining the efficiency of the emergency stop device.
A disadvantage of this pre-known device is that it is not operable in certain types of elevators, e.g., indirect hydraulical elevators. Additionally, the evaluation unit is placed on the elevator where it can be damaged during the test.